Realistically, what is the biggest franchise that Microsoft can buy out that would give them first place in console sales?

[GTAexpert]

DrDoomz said:
Imo, MS is pretty good on the a FPS/Action genre and sports genre as well.

However, if they buy ES and come out with a moddable Skyrim sequel, I would def buy me an Xbox....

Do they have any non-shooter action game or sports game? I don't think so.